An OLED is a light-emitting element that generates light using energy emitted from excitations created by the recombination of electrons injected through a cathode and holes injected through an anode. OLEDs have a variety of advantages, such as low-voltage driving, self-emission, a wide viewing angle, high resolution, natural color reproducibility, and short response times. OLED lighting is also advantageous because it is a diffusive light source that minimizes glare. OLEDs generate less heat as compared with a traditional light emitting diode (LED), which saves power and material usage.
OLEDs may be applied to a variety of devices, such as portable information devices, cameras, watches, office equipment, information display windows of vehicles, televisions (TVs), display devices, illumination devices, and other electronic devices.
One challenge for OLED lighting is light efficiency loss, generally caused by a difference of refractive index between layers that results in light scattering or reflection within the device, or by light absorption within a layer. To improve the efficiency, one or more light extraction substrates may be used in an OLED device. A large number of different types of light extraction layers have been designed for use in OLEDs as well as other applications. Examples of light extraction substrates include those described in Korean Patent Application No. 2016-034791A, filed Mar. 23, 2016, which is incorporated by reference herein in its entirety.
The light extraction substrates described in Korean Patent Application No. 2016-034791A can be formed by providing one or more precursors on a base substrate and thermally treating each respective precursor layer in a specialized oven. Thermal treating typically requires temperatures up to 500° C. for a duration lasting 15 to 30 minutes or more for each individual layer. This process is time consuming, which increases manufacturing costs. Further, the high temperatures required for thermal treating are unsuitable for some base substrate materials. Therefore, a more rapid process that reduces the required treating temperature is needed for forming light extraction substrates for OLEDs.